Interest and utilisation of polycrystalline boron-doped diamond (pBDD) as an electrode material has rapidly grown over the last decade, due to its unique properties and advantages over other available electrode materials. The possibility of lower detection limits and an increased range of detectable analytes has seen pBDD flourish in electroanalysis. Due to its stability at high temperatures, pressures and acidity, pBDD also has the potential to perform electrochemistry in extreme conditions. These unique properties, however, make the material difficult to manipulate in order to produce well defined and reproducible electrodes. Deviations in electrical and electrochemical responses can also arise from sample to sample, due to differing synthesis conditions and experimental set-ups. This thesis aims to characterise pBDD available from a commercial source and through fabrication of electrodes of various designs, best utilise the material in the electroanalysis of several species. Characterisation is performed using high resolution microscopic and spectroscopic techniques which show a heterogeneous material with negligible levels of non-diamond like carbon and boron concentrations of at least 1 x 1020 atoms cm-3 throughout. Disc electrodes, fabricated using laser machining, are electrochemically characterised showing low background currents, wide solvent windows and close to reversible behaviour for Ru(NH3)6 3+/2+, IrCl6 2-/3- and Fe(CN)6 3-/4. Functionalisation of these pBDD disc electrodes with nanoparticles enables the detection of dissolved oxygen and glucose to detection limits of ~ ppb. Furthermore, the fabricated electrodes are used in the study of Pb deposition and stripping behaviour at a pBDD surface, as well as Pb2+ detection. The last chapter in this thesis details the next step in diamond electrode development; the fabrication of all-diamond electrodes, where the pBDD is insulated with intrinsic diamond. Two electrode geometries are described, the first being a tubular flow ring electrode which has well-defined hydrodynamics and is used in the detection of dopamine. The second all-diamond geometry is a dual band electrode which it utilised as a solution conductivity sensor.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:582185 |
| Date | January 2011 |
| Creators | Hutton, Laura A. |
| Publisher | University of Warwick |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://wrap.warwick.ac.uk/55512/ |
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